Nanoscience is the study of phenomena on a nanometer scale. The first principle is to reduce the size in nanometer range. In recent age, with potential applications in virtually every existing industry and new applications yet to be discovered. Among different branches of nanoscience, nanomaterials chemistry is an important branch in respect to their bio-medical applications.
In India, "Concept of reduction in particle size of metals is prevailing since Charaka Samhita (1500 BC). For a metallic preparation of Lauhadi Rasayana, iron is heated up to red hot and quenched in some liquid media immediately until flakes of iron become in fine powder form."